Heating system

ABSTRACT

A series-loop heating system provides heat for a plurality of controlled temperature zones within a large building or several buildings and utilizes and incorporates within the system both the domestic hot water system and the standard structural members normally associated with such a building or buildings. The heating system includes a normally closed circuit with a plurality of heat exchange coils connected to the circuit in series through which the domestic hot water is continually circulated. Each controlled temperature zone includes at least one heat exchange unit and each heat exchange unit includes one of the heat exchange coils over which air is passed when heating the zone.

United States Patent [15] 3,655,127 [451 Apr. 11, 1972 Piper [54] HEATING SYSTEM [72] Inventor: James R. Piper, 6405 West Chartres Drive, Palos Verdes, Calif. 90274 [22] Filed: Feb.1l, 1970 [21] Appl.N0.: 10,456

[52] U.S.Cl ..237/8,237/13,237/l9 [51] Int. Cl ..F24d 3/08 [58] FieldofSearch ..237/8,5,19,56

[5 6] References Cited UNITED STATES PATENTS 1,973,842 9/1934 Broderick ..237/8 3,236,453 2/1966 Raymond... .....237/8A 2,021,583 11/1935 Whitley ..165/48 1,715,040 5/1929 Mauck ..237/8 1,937,909 12/1933 Paige ..237/8 2,019,991 11/1935 Nilson..... .237/8A 2,348,610 5/1944 Colby ..237/19 3,526,361 9/1970 Piper ..237/19X l 17/666 7/0/ OF HOW (AWITOEV FOREIGN PATENTS OR APPLICATIONS 1,250,618 9/1967 Germany ..237/8 Primary Examiner-Edward J. Michael Attorney-Lyon & Lyon [57] ABSTRACT A series-loop heating system provides heat for a plurality of controlled temperature zones within a large building or several buildings and utilizes and incorporates within the system both the domestic hot water system and the standard structural members normally associated with such a building or buildings. The heating system includes a normally closed circuit with a plurality of heat exchange coils connected to the circuit in series through which the domestic hot water is continually circulated. Each controlled temperature zone includes at least one heat exchange unit and each heat exchange unit includes one of the heat exchange coils over which air is passed when heating the zone.

14 Claims, 2 Drawing Figures Patented April 11, 1972 1 3,655,127

2 Sheets-Sheet 3 mvsmozz 14/1455 e P/Pe i BY HEATING SYSTEM This invention relates to a system for heating a plurality of separate zones within a building or several buildings and, in particular, to a system for circulating air passed heat exchange coils and distributing the same throughout these zones wherein the domestic hot water is used in heating this circulatmg arr.

Heating systems normally used by todays building industry are expensive because of the cost of the equipment for such systems and the cost of installing these systems which normally required extensive alterations of the standard building structures. Series-loop heating systems have performed well in the past and are desireable from a cost standpoint, however,

their use has been limited because such systems have previously been considered to be impractical for use in several buildings or in a large building, such as a large apartment house, because of the wide temperature differential required throughout these several buildings or throughout the large building. Moreover, past series-loop heating systems have also failed to fully utilize the standard building structures and thereby further lower the cost of installation.

Therefore, it is a primary object of this invention to provide a series-loop heating system which will meet the varying demand associated with several buildings or a single large buildmg.

Another object of this invention is to provide a heating system for a building or several buildings which will utilize and incorporate into the system both the domestic hot water system and the standard structural members normally associated with such a building or buildings.

A further object of this invention is to provide a heating system for a building or buildings with individually controlled temperature zones.

A still further object of this invention is to provide a heating system having a normally closed circuit, through which a heating medium continuously circulates, which avoids the use of valves or other similar mechanisms to control and divert the flow of the heating medium in the circuit.

Another object of this invention is to provide a heating system which will adjust to operate efficiently and economically when varying demands are made on the entire system and/or when varying demands are made on portions throughout the system.

In accordance with these and other objects, the heating system of this invention includes a valve free normally closed circuit having in series the heat exchange coils of a plurality of heat exchange units, with domestic outlets in the circuit for selective extraction of domestic hot water from the system and with water supply inlets in the circuit for replacing extracted water. The system also includes pumps which cause the domestic hot water, which acts as a heating medium, to be continually circulated throughout the circuit and through each heat exchange coil and heater units spaced at predetermined intervals about the circuit to maintain the temperature of the heating medium in the circuit within desired limits. The heat exchange units of the system provide individually controlled temperature zones and each unit includes a thermostatically controlled fan which is adapted to pass air over and around a heat exchange coil and then distribute the air throughout a zone when heating that zone.

Still another object of this invention is to provide a heating system for a building or several buildings which is easy and relatively inexpensive to install and which utilizes low cost equipment having minimum maintenance requirements.

Other and more detailed objects and advantages of this invention will readily appear from the following detailed description and the accompanying drawings:

In the drawings:

FIG. 1 is a diagrammatic view illustrating a typical preferred form of the system.

FIG. 2 is a perspective view partially in section illustrating a heat exchange unit used in the system.

Referring now in detail to the drawings, the heating system, generally designated 10, include a normally closed loop circuit 11, which provides for communication of the heating medium, which is also the domestic hot water, throughout the circuit 11 and to the domestic hot water outlets 12 in the building or buildings. While only a single system 10 has been shown it should be recognized that in some instances it may be desireable to employ more than one complete system 10 in a single building or more than one for the several buildings even though this single system 10 is adapted to accommodate a great many controlled temperature zones. The circuit 10 is adapted to employ piping of the type normally found in a domestic hot water system and, as will be made apparent from the following discussion, the size of the piping and the length of the piping required will be held to a minimum because of the design of this system.

As seen in FIG. 2, the circuit 11 includes a train of heat exchange coils 13, a number of standard centrifugal pumps 14, and a number of heater units or boilers 15, all of which are connected to the circuit 11 in series.

Normally, the number of pumps 14 and the number of boilers 15 are the same, with each pump 14 connected to the circuit 11 in close association with a boiler 15. However, in some instances where the circuit 11 required is particularly lengthy, for example when the system is used to heat several buildings which are located far apart, more pumps 14 than boilers 15 may be desirable. Preferably, the pumps 14 of the system are adapted to maintain a flow of the heating medium in the circuit 11 at about 25-40 gallons per minute.

The boilers 15 are generally equally spaced throughout the circuit 11 and normally, there is one boiler 15 required for every 10 or 12 coils 13, with each boiler 15 having a maximum output of 600,000 BTUs. However, because of the varying demand of different type buildings, the number of heat exchange coils 13 per boiler 15 may range from as few as eight to as many as twenty.

Each boiler 15 is of a relatively conventional low temperature, copper water tube type and is gas operated. As stated before, each boiler 15 is connected in series with the circuit 11 and the boilers are adapted to maintain the temperature of the water in the circuit 11 at about F. The boilers 15 heat the water already circulating in the circuit 11 and also heat any new water added to the system through water supply inlets 16, each of which is connected to the circuit 11 immediately upstream of a boiler 15. Each boiler 15 also includes a thermostat control unit, not shown, which senses the temperature of the water in the circuit immediately upstream of the boiler to turn the boiler 15 on when the circulating water is too cold or fresh water is being added due to a loss of hot water through an opened hot water outlet 12, and to turn the boiler off when the water reaches a maximum temperature and also to modulate the input to the boiler within these on and off limits. Check valves 17 on the supply inlets 16 prevent undesired flow of water through those inlets.

As stated previously, each controlled temperature zone includes a heat exchange unit, generally designated 30, and

. shown in detail in FIG. 2. Each heat exchange unit 30 includes within it one of the heat exchange coils 13. The heat exchange coil is mounted between a pair of the normal parallel structural members or floor joists 31 near one end of a room in a building. Opposite the heat exchange coil 13 and also mounted between the same joists 31 at the other end of a room is a partition wall 32. The partition wall 32 is provided with an opening 33 which acts as an inlet for air. The floor 34 of the room and an enclosing cover member 35 form a plenum 36 between the heat exchange coil 13 and the partition wall 32, with the joists 31 acting as the side walls of the plenum 36. An electric fan 37 is connected to the other side of the partition wall 32 outside the plenum 36. The fan 37 is operated by a thennostat control 38 which is located in the controlled temperature zone. The outlet of the fan 37 is connected to the inlet opening 33 of the partition wall 32 to provide a passage for air between the fan 37 and the plenum 36. The plenum is sufficiently large in order to provide a slow air movement which causes improved heat transfer between the air and the heat exchange coil 13 and also causes less air disturbance in the area to be heated. All the air passing through the plenum 36 must pass over the heat exchange coil 13 before entering the area to be heated.

An inlet air flow register, not shown, and an outlet air flow register 39 are located between the joists and on the floor 34 at opposite ends of the room. The inlet air flow register allows cool air to be drawn from the controlled temperature zone by fan 37 while air flow register 39 allows the heated air to pass from the plenum into the zone.

The operation of the system is as follows:

Water which has been heated by the boilers is continually circulated through the closed loop circuit 11 by the pumps 14. This hot water passes through each heat exchange coil 13 since they are connected in series with the circuit 11. When heat is required in a zone, a thermostat 38 in that zone activates the electric fan 3'7 which causes cold air to be drawn in from the zone through the inlet air flow register. The fan 37 then forces this air through the plenum 36 and across the heat transfer area of the heat exchange coil 13 where the air is heated. The heated air then passes out through the outlet register 39 into the zone. When the zone is sufficiently heated, the thermostat 38 turns off the fan 37 and the flow of hot air into the room discontinues. The hot water continues to flow through the heat exchange coil 21, but since the water in the circuit 11 is only about 140 F. the zone temperature is not affected when the fans are stopped due to the relatively low temperature differential from the coil to the room and the insulation therebetween whereby heat transfer is minimal.

It has been found that because of the segmenting of the heater units or boilers, that the temperature drop in the circulating hot water will be held within required operating conditions as it passes throughout the circuit 11 and through the several heat exchange coils 13 between boilers 15, even under maximum demand. Maximum demand is the situation where heating is required in all the controlled temperature zones of the system. It should be evident that in a system having several controlled temperature zones this situation rarely arises, because among other reasons, it is unlikely that all the zones will be occupied and thereby all require heating at any given time and since each heat exchange unit 30 in each zone operates independently when only some of the zones require heating there will be less heat exchange units 30 operating and there will be less of a demand on the system.

A significant feature of this invention is its ability to adapt to these varying demands. Because the operation of each boiler is controlled independently by the thermostat controls which sense the temperature of the water in the circuit, the system will require less boilers to operate when demand on the system 10 decreases. In this regard, it should be noted that not only will the total demand on the entire system vary during operation of the system, it may also vary throughout portions of the system. It should be evident that this system will readily adapt to these variations also. It should also be noted that this socalled segmenting has many other advantages over a system with a single large heater unit. The use of the several smaller heater units avoids the necessity of the relatively large piping of a single unit. Moreover, the initial costs, the installation costs and the maintenance costs are generally lower where several small units are employed. In addition, a breakdown of one of the smaller units of this system will not completely disable the entire system.

This invention includes all the advantages previously recognized in a series loop system while avoiding several disadvantages thought apparent in such systems. This system has the advantage of a relatively low installation cost which is due in part to the utilization of both the standard structural members and the domestic hot water system into this system. Otherwise wasted space between the floor or ceiling joists is used to form a part of the system. Thus, ducts as normally conceived are not required. In addition, since this system is a series loop system the length of pipe the system requires is held to a minimum. Moreover, the heating medium is circulated throughout the system without the need for expensive valve controls.

This invention provides a relatively low cost heating system which includes individually controlled temperature zones. It is particularly adapted for use in large buildings or for use in several small buildings and it operates at a high efficiency.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

Iclaim:

1. A heating system for a building or buildings adapted to heat a plurality of separately controlled temperature zones, within the building or buildings comprising:

a single continuous, normally closed loop circuit for communicating hot water having at least one domestic outlet for selective extraction of hot water and at least one supply inlet for replacing extracted water;

a plurality of heat exchange coils for heating air and connected in series in said loop circuit;

a plurality of heaters for maintaining the water in said loop circuit at a predetermined temperature and connected in series in said loop circuit;

pump means for continuously circulating the water around said loop circuit and through each said heat exchange coil and each said heater and also connected in series in said loop circuit; and

independently and selectively operable heat exchange units for providing heated air to the zones, each said heat exchange unit including one of said heat exchange coils and air circulating means associated with said heat exchange coil being adapted to pass air over said heat exchange coil into a zone requiring heated air.

2. The system set forth in claim 1, wherein each said heater comprises a thermostatically controlled boiler which is independently operable whereby the number of boilers operating at any one time may vary according to the demand on the system.

3. The system set forth in claim 1, wherein said heaters are connected to said loop circuit at predetermined spaced locations and a predetermined number of heat exchange coils are connected to said loop circuit between each said heater.

4. The system set forth in claim 3 wherein each said heater is of the type having an output of from 300,000 to 600,000 BTUs, and the number of heat exchange coils between each said heater ranges from eight to 20.

5. The system set forth in claim 4, wherein said pump means has a capacity for maintaining a flow rate of the water in said loop circuit of about 25 to 40 gallons per minute.

6. The system set forth in claim 1, wherein said pump means comprises a plurality of pumps, with at least one of said pumps associated with each said heater.

7. The system set forth in claim 1, wherein each said supply inlet is located in said loop circuit directly downstream from a said heater.

8. The system set forth in claim 1, wherein said air circulating means is an electric fan operated by a thermostat control responsive to the air temperature in a controlled temperature zone.

9. The system set forth in claim 1, wherein means are provided to separate each said heat exchange coil from the controlled temperature zones thereby preventing any significant heat transfer to the zones when said air circulating means is not operating.

10. The system set forth in claim 1, wherein said heaters each include a conventional boiler for maintaining the water in said loop circuit at about F to F.

11. The system set forth in claim 1, wherein each said heat exchange unit includes a plenum for directing the air from said air circulating means over said heat coil, each said plenum being formed in part by a pair of conventional structural members of a building which are positioned in a spaced and parallel relation, such as joists and studs.

falls below a predetermined minimum temperature, to turn said heat off when the water temperature exceeds a predetermined maximum temperature and to modulate the input to said heater within these off and on limits.

14. The system set forth in claim 13, wherein each said thermostat senses the temperature of the water in said loop circuit immediately downstream of each said heater. 

1. A heating system for a building or buildings adapted to heat a plurality of separately controlled temperature zones, within the building or buildings comprising: a single continuous, normally closed loop circuit for communicating hot water having at least one domestic outlet for selective extraction of hot water and at least one supply inlet for replacing extracted water; a plurality of heat exchange coils for heating air and connected in series in said loop circuit; a plurality of heaters for maintaining the water in said loop circuit at a predetermined temperature and connected in series in said loop circuit; pump means for continuously circulating the water around said loop circuit and through each said heat exchange coil and each said heater and also connected in series in said loop circuit; and independently and selectively operable heat exchange units for providing heated air to the zones, each said heat exchange unit including one of said heat exchange coils and air circulating means associated with said heat exchange coil being adapted to pass air over said heat exchange coil into a zone requiring heated air.
 2. The system set forth in claim 1, wherein each said heater comprises a thermostatically controlled boiler which is independently operable whereby the number of boilers operating at any one time may vary according to the demand on the system.
 3. The system set forth in claim 1, wherein said heaters are connected to said loop circuit at predetermined spaced locations and a predetermined number of heat exchange coils are connected to said loop circuit between each said heater.
 4. The system set forth in claim 3 wherein each said heater is of the type having an output of from 300,000 to 600,000 BTUs, and the number of heat exchange coils between each said heater ranges from eight to
 20. 5. The system set forth in claim 4, wherein said pump means has a capacity for maintaining a flow rate of the water in said loop circuit of about 25 to 40 gallons per minute.
 6. The system set forth in claim 1, wherein said pump means comprises a plurality of pumps, with at least one of said pumps associated with each said heater.
 7. The system set forth in claim 1, wherein each said supply inlet is located in said loop circuit directly downstream from a said heater.
 8. The system set forth in claim 1, wherein said air circulating means is an electric fan operated by a thermostat control responsive to the air temperature in a controlled temperature zone.
 9. The system set forth in claim 1, wherein means are provided to separate each said heat exchange coil from the controlled temperature zones thereby preventing any significant heat transfer to the zones when said air circulating means is not operating.
 10. The system set forth in claim 1, wherein said heaters each include a conventional boiler for maintaining the water in said loop circuit at about 140* F to 150* F.
 11. The system set forth in claim 1, wherein each said heat exchange unit includes a plenum for directing the air from said air circulating means over said heat coil, each said plenum being formed in part by a pair of conventional structural members of a building which are positioned in a spaced and parallel relation, such as joists and studs.
 12. The system of claim 11, wherein said air circulating means and said heat exchange coil in each said heat exchange unit are mounted within and directly between said pair of conventional structural members forming in part said plenum and at opposite ends thereof.
 13. The system set forth in claim 1, wherein each said heater includes a thermostat control which senses the temperature of the water in said loop circuit, said thermostat control being adapted to turn said heater on when the water temperature falls below a predetermined minimum temperature, to turn said heat off when the water temperature exceeds a predetermined maximum temperature and to modulate the input to said heater within these off and on limits.
 14. The system set forth in claim 13, wherein each said thermostat senses the temperature of the water in said loop circuit immediately downstream of each said heater. 